Currently, the behavior of putting a null value is inconsistent: it is a delete for RocksDB, and not supported in in-memory store, and on a case-by-case basis for remote tables. It is desirable to unify the behavior. Furthermore, it eases the writing of a change captured stream to a table. A change captured stream contains typically 3 types of events: INSERT, UPDATE and DELETE, and they need to be applied properly when written to a table to produce a correct snapshot. In a change captured stream the payload of a DELETE event is typically is null, and this would result in a delete operation to a table in sendTo() operator.